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Biomedical subjects

Neil Powe

Publications and source records attributed to Neil Powe.

11 recordsLinked to original sources
PubMed2006

Haplotype of signal transducer and activator of transcription 3 gene predicts cardiovascular disease in dialysis patients.

Signal transducer and activator of transcription 3 (STAT3) protein has been linked to cardiovascular disease (CVD) through multiple pathways in experimental and animal studies. STAT3 gene variation was examined as a predictor of incident CVD in a subcohort of 529 incident white dialysis patients. Fifteen single-nucleotide polymorphisms of the STAT3 gene were genotyped. Haplotypes were estimated using software PHASE 2.1, and associations with first CVD event were tested using Cox proportional hazards analysis. Adjusted global tests of haplotype association with incident CVD and inflammation markers were performed using permutated P value in R-package Haplo.score. An a priori specified additive genetic model was assumed for haplotype analysis. Both genotypes (four single nucleotide polymorphisms with P < 0.001) and haplotypes (P = 0.002 overall) were associated with incident CVD. Two major haplotype blocks, blocks A and C, were identified. Compared with common haplotype A-1, A-3 was associated with a hazard ratio (HR) of 0.70 (95% confidence interval [CI] 0.51 to 0.94) for CVD events after adjustment for covariates including C-reactive protein (CRP) and interleukin 6. Compared with common haplotype C-1, C-3 was associated with an adjusted HR of 2.12 (95% CI 1.25 to 3.57) for CVD events. Associations were independent of inflammation markers, but IL-6 levels were 14% lower (geometric mean ratio 0.86; 95% CI 0.77 to 0.96) per copy of haplotype A-3 compared with haplotype A-1 in block A after adjustment for CRP and other risk factors (P = 0.008). Variation in the STAT3 gene is associated with the risk for CVD among white dialysis patients independent of serum IL-6 and CRP levels.

Aged↗
PubMed2006

Defining "success" in recruitment of underrepresented populations to cancer clinical trials: moving toward a more consistent approach.

Although medically underserved groups bear a heavy burden of cancer disease and governmental agencies have required inclusion of minorities and women in cancer clinical trials since 1993, many of these groups are underrepresented in cancer prevention or treatment clinical trials. To assess and enhance recruitment of underrepresented populations into cancer-related clinical trials, investigators and governmental agencies need consistent measurement approaches for recruitment that can be applied to diverse settings where trials are conducted. We conducted a systematic review to evaluate what measurement approaches were used to evaluate the success of recruitment of underrepresented groups into cancer prevention or treatment trials, and whether these recruitment goals were stated a priori. Only two articles reported an a priori recruitment goal. The recruitment measurement approaches varied considerably, with no consistent standard, especially for individual trials. By using the empiric evidence from this review in conjunction with the National Institutes of Health (NIH) guidelines, we constructed a framework for choosing consistent a priori recruitment goals for underrepresented groups based on the research question and study location. Using consistent measurement approaches for underrepresented groups will improve comparability of recruitment strategies across trials, improve equity in distribution of benefits and burdens of cancer-related clinical trials, and may improve applicability of trial results to multiple populations.

Clinical Competence↗
PubMed2006

Self-perceived loss of control and untreated dental decay in African American adults with and without sickle cell disease.

The aim of this cross-sectional study was to investigate the association between self-perceived loss of control as measured by dental external locus of control summary scores, with the amount of untreated dental decay in African American adults with sickle cell disease (SCD) and African Americans adults without SCD. The sample included 102 subjects with SCD and 103 subjects without SCD matched on age, sex, and recruitment location (mean age of all subjects 35.4 years, 55.6% female). Subjects with SCD in the highest quartile for dental external locus of control summary scores had 2.58-fold (CI 1.05, 6.34) as much untreated decay as those in the lowest quartile (p<.05) in multivariable analysis using the negative binomial regression model. For subjects without SCD, those in the highest quartile for dental external locus of control summary scores had 3.00-fold (CI 1.38, 6.49) as much untreated decay as those in the lowest quartile (p<.05) using similar analysis. This study showed that higher dental external locus of control is associated with increased untreated tooth decay, both for African Americans with and without SCD and that the magnitude of the association did not differ across groups.

Adolescent↗
PubMed2005

Fourteen-year (1987 to 2000) trends in the attack rates of, therapy for, and mortality from non-ST-elevation acute coronary syndromes in four United States communities.

During the past 2 decades, randomized trials have proved the efficacy of several treatments for non-ST-elevation acute coronary syndromes (NSTE-ACSs), including aspirin, beta blockers, and coronary revascularization. However, the cumulative effectiveness of these evolving therapies in actual clinical practice remains unknown. The Atherosclerosis Risk In Communities (ARIC) surveillance study uses rigorous prospective community surveillance to monitor the epidemiology of coronary heart disease among subjects who are 35 to 74 years of age and reside in 4 United States communities, with a population totaling 370,000 subjects. We identified 6,379 ARIC surveillance patients who were hospitalized with NSTE-ACS (defined as cardiac chest pain and ST depression or T-wave inversion on the presenting electrocardiogram) between 1987 and 2000 and then analyzed 30-day and 1-year mortalities by calendar year of admission. Using logistic regression, 30-day mortality was modeled first using predictor variables of the calendar year, ARIC community, and indicators of severity and co-morbidity and then by adding variables for treatment with aspirin, beta blockers, and coronary revascularization to this model. Crude 30-day mortality decreased from 8.6% in 1988 to 3.6% in 2000 (p for trend <0.001), a trend that remained significant (p = 0.006) after adjustment for case severity and co-morbidity. The trend became nonsignificant after adjustment for treatment variables, suggesting that newer treatments may explain the improved survival. In conclusion, 30-day mortality from NSTE-ACS has decreased as treatment has improved.

Adrenergic beta-Antagonists↗
PubMed2005

Do drug prices reflect development time and government investment?

BACKGROUND: Lengthy development times are cited by the pharmaceutical industry as one reason for high drug prices. OBJECTIVE: We compared the prices of different groups of drugs after accounting for development time, government support, market size, and other drug characteristics. DESIGN: We conducted a retrospective study of 180 human therapeutic drugs categorized into 8 drug groups by assembling data on drug development times, government support, drug characteristics, and prices. MEASURES: First, we compared the development time and level of government support across the 8 drug groups. Second, we assessed the independent effect of drug group on median price per day in a multivariable analysis, controlling for development time and all other variables. RESULTS: Thirty percent of antiretroviral drugs had government patents compared with 16% of other infectious disease drugs, 6% of cancer drugs, and less than 6% of any other drug group (P < 0.002). Fifty percent of antiretrovirals had NIH trials listed in the new drug application for approval by the Food and Drug Administration compared with less than 6% of any other drug group (P < 0.001). More antiretroviral and cancer drugs received fast track status and accelerated review during regulatory review by the Food and Drug Administration (P < 0.001). The median price of antiretrovirals was 8 US dollars per day more, cancer drugs 11 US dollars per day more, than the reference group after adjustment for other variables (P < 0.001). Development time was not associated with drug price. CONCLUSIONS: Antiretroviral and cancer drugs, even after accounting for development time, are among the most highly priced medications. Notably, drugs with rapid development and more government support did not have lower drug prices.

Chemistry, Pharmaceutical↗
PubMed2002

Time trends in high blood pressure control and the use of antihypertensive medications in older adults: the Cardiovascular Health Study.

BACKGROUND: Control of high blood pressure (BP) in older adults is an important part of public health efforts at prevention. OBJECTIVE: To assess recent time trends in the awareness, treatment, and control of high BP and in the use of medications to treat high BP. METHODS: In the Cardiovascular Health Study, 5888 adults 65 years and older were recruited from 4 US centers. At baseline, participants underwent an extensive examination that included the measurement of BP, use of medications, and other risk factors. Participants were followed up with annual visits that assessed BP and medication use from baseline in 1989-1990 through the examination in 1998-1999. The primary outcome measures were control of BP to levels lower than than 140/90 mm Hg and the prevalence of use of various classes of antihypertensive medications. RESULTS: The awareness, treatment, and control of high BP improved during the 1990s. The proportions aware and treated were higher among blacks than whites, though control prevalences were similar. For both groups combined, the control of high BP to lower than 140/90 mm Hg increased from 37% at baseline to 49% in 1999. The 51% whose BP was not controlled generally had isolated mild to moderate elevations in systolic BP. Among treated persons, the improvement in control was achieved in part by a mean increase of 0.2 antihypertensive medications per person over the course of 9 years. Improved control was also achieved by increasing the proportion of the entire Cardiovascular Health Study population that was treated for hypertension, from 34.5% in 1990 to 51.1% in 1999. Time trends in antihypertensive drug use were pronounced. Among those without coronary disease, the use of low-dose diuretics and beta-blockers decreased, while the use of newer agents, such as calcium channel blockers, angiotensin-converting enzyme inhibitors, and alpha-blockers increased. CONCLUSIONS: While control of high BP improved in the 1990s, about half the participants with hypertension had uncontrolled BP, primarily mild to moderate elevations in systolic BP. Low-dose diuretics and beta-blockers--the preferred agents since 1993 according to the recommendations of the Joint National Committee on the Detection, Evaluation and Treatment of High Blood Pressure--remained underused. More widespread use of these agents will be an important intervention to prevent the devastating complications of hypertension, including stroke, myocardial infarction, and heart failure.

Age Factors↗
PubMed2002

Weight-modification trials in older adults: what should the outcome measure be?

BACKGROUND: Overweight older adults are often counseled to lose weight, even though there is little evidence of excess mortality in that age group. Overweight and underweight may be more associated with health status than with mortality, but few clinical trials of any kind have been based on maximizing years of healthy life (YHL), as opposed to years of life (YOL). OBJECTIVE: This paper examines the relationship of body mass index (BMI) to both YHL and YOL. Results were used to determine whether clinical trials of weight-modification based on improving YHL would be more powerful than studies based on survival. DESIGN: We used data from a cohort of 4,878 non-smoking men and women aged 65-100 at baseline (mean age 73) and followed 7 years. We estimated mean YHL and YOL in four categories of BMI: underweight, normal, overweight, and obese. RESULTS: Subjects averaged 6.3 YOL and 4.6 YHL of a possible 7 years. Both measures were higher for women and whites. For men, none of the BMI groups was significantly different from the normal group on either YOL or YHL. For women, the obese had significantly lower YHL (but not YOL) than the normals, and the underweight had significantly lower YOL and YHL. The overweight group was not significantly different from the normal group on either measure. CONCLUSIONS: Clinical trials of weight loss interventions for obese older women would require fewer participants if YHL rather than YOL was the outcome measure. Interventions for obese men or for the merely overweight are not likely to achieve differences in either YOL or YHL. Evaluations of interventions for the underweight (which would presumably address the causes of their low weight) may be conducted efficiently using either outcome measure.

Journal Article↗
PubMed2002

Geographic socioeconomic status, race, and advanced-stage breast cancer in New York City.

OBJECTIVES: This study examined the association between a residential area' socioeconomic status (SES), race, and advanced-stage breast cancer in New York City. METHODS: The cross-sectional study design used breast cancer information for 37 921 cases diagnosed in New York City from 1986 to 1995. Residential education and income levels were based on the 1990 census and ascribed to each case by zip code. Associations between race, area SES, and advanced-stage breast cancer stage, and the interaction between race and SES, were evaluated in bivariate and multivariate analyses. RESULTS: After adjusting for age and year at diagnosis, living in areas with lower levels of education and income increased the odds of presenting with advanced-stage breast cancer by 50% for Black women and by 75% for White women. No significant qualitative interaction was present between area SES and race. CONCLUSIONS: This study confirmed independent racial and socioeconomic differences in the risk of advanced-stage breast cancer in a large and diverse population. The results emphasize the need to improve screening practices and clinical treatment in both high-risk populations and high-risk geographic areas.

Adult↗
PubMedDate not supplied

The association between sickle cell disease and dental caries in African Americans.

This study sought to determine whether there was an association between sickle cell disease (SCD) and dental caries in African-American adults. A sample of 102 African-American adult patients with SCD from Washington, D.C., and Baltimore, Maryland, were matched to 103 African-American adult subjects, who did not have SCD. The match was by age, gender and recruitment location. Each subject underwent a standardized oral examination as well as an interview to ascertain risk factors for dental caries. For individuals with incomes of less than dollars 15,000, subjects with SCD had more decayed (10.36 versus 1.58) and fewer filled (2.86 versus 8.45) surfaces compared to subjects without SCD with both differences being statistically significant (p<0.05) after adjusting for age and gender. The results suggest that low-income African Americans with SCD may be at increased risk for dental caries and are less likely to receive treatment with a restoration.

Adult↗
PubMedDate not supplied

Are development times for pharmaceuticals increasing or decreasing?

This study examines trends in drug development times. Longer clinical trial times have been described as one factor leading to higher drug prices. Previous reports on development times have been based on proprietary data. We examined trends in development times for 168 drugs with data collected from publicly available sources. The median clinical trial and regulatory review periods for drugs approved between 1992 and 2002 were 5.1 and 1.2 years, respectively. Clinical trial periods have not increased during this time frame, and regulatory review periods have decreased. Therefore, it is unlikely that longer clinical trial times are contributing to rising prescription drug prices.

Clinical Trials as Topic↗